My car will boost when cold the just like not boost anything of 5 PSI WTF! 2000 audi a4 b5 1.8t with apr chip tiptronic.
It'll run like a champ for like 10 maybe 15 mins then just crap out feels like i'm drivin it on just 4 cylinders minus turbo! any suggestions would be greatly appreciated!

 

Well it sounds like the ECU will allow everything to perform as it should while it's in closed-loop operation, and then when it's sufficiently warmed up and goes into open-loop mode, it puts itself into a "safety boost" sort of mode. I'd scan the ECU even if you don't have a CEL and see if something is buried in there. Although I'm not sure on these cars, on most cars that I've had, the only real parts that were affected by cold vs warm running were O2 sensors, and maybe the fuel pump or regulator. When cold, the car runs on a preset fuel/timing map that is coded into the ECU (since the O2 sensors have to heat up before they can be relied upon for controlling the operation of the engine). Once the car is warmed up, feedback from the O2 sensors is no longer ignored, and fuel demands are interpolated from O2 sensor feedback. I'd look into either O2 problems, or possibly a loose or cracked vacuum line in some area dealing with the fueling system. If there is such a problem with vacuum reference to the fuel system, I could see how, when the car is warm, the ECU is calling for X amount of fuel, but the system can't supply it due to a faulty vacuum signal or crappy pre-catalytic converter O2 sensor reading. Sorry if this isn't much to go on, but it's a start.

 

i bet its a bad coilpack or two...